This invention relates to protective metal coatings on uranium and the alloys thereof and is more particularly directed to a method of improving the adherence thereto of a coating formed by successive electrodeposits of copper and lead.
The rapidly increasing availability of depleted uranium has led to the fairly recent use thereof for the fabrication of items in which an unusually high density is an important requirement, as, for example, in counterweights for aircraft use or in projectiles fired from military weapons. However, the full potential of depleted uranium as a structural material has yet to be realized primarily because of the surface corrosion invariably encountered upon the exposure thereof to the atmosphere and aqueous solutions and, in addition, because of the pyrophoric reaction frequently incurred during the machining thereof to a desired configuration. While the surface corrosion of uranium can be satisfactorily prevented by a suitable metallic coating thereon, the machining problems have yet to be overcome.
It has therefore been proposed to shape uranium stock to a desired configuration by means of hydrostatic extrusion at room temperature. In the course of developing a suitable process of cold extrusion, it was discovered that while successive layers of copper and lead on the uranium surface afforded the type of lubrication required during the passage thereof through a die orifice of smaller diameter, the adherence of the copper to both the uranium and the lead was insufficient to withstand the relatively high pressures required to effect hydrostatic extrusion.